This invention relates generally to a miniature motor, and more particularly to a miniature motor comprising a hollow tubular large case having a magnet disposed along the inner circumferential surface thereof, and a small case fitted to the large case and having brush holders, made of a synthetic resin, and magnet retaining bosses making contact with the magnet, in which the small case is fitted to the large case in a state where the magnet retaining bosses are brought into contact with the magnet by providing boss insert holes into which the magnet retaining bosses are press-fitted.